Police said Trinity Ross was declared brain dead after the shooting in her house in the 10500 block of Monroe Avenue four days after her fourth birthday. She was taken off life-support machines a week later.

Investigators said that the woman watching Ross and two other young children briefly left the room. One of the other children picked up a handgun that had been left in his reach and fired a shot, hitting Ross.

Police said when they found the gun in the house, it had four additional unspent rounds in it.

"Why was the gun sitting out?" said neighbor Misty Honnold. "I'm sure those are only questions the parents can answer, and how did the child get access to the guns? Those are things that traumatize all of us."

Relatives of the three people killed in last year's shootings at the Overland Park Jewish Community Center and a nearby nursing home have a plan to remember their loved ones with random acts of kindness.